Greetings,
I have tried factory defaults + without Magic Lantern. I wouldn't say this is totally random, although sometimes it seems like it. For example:
(8 other samples at Index of /Qwerty/t3i_randomAutoShooting/
)I stopped to observe this, so I pointed my camera down at my feet and tilted the camera up toward the sky. Nothing.
However, when I started at the sky and tilted it back down toward my feet -- EVERY TIME it would snap a photo at the treeline automatically. I made sure to use only few fingers of both hands to hold the camera in a way that would absolutely verify that I wasn't losing my mind and that the camera really was automatically taking photos.
I also tried changing it from automatic focus to manual focus on the lens. Same results.
I could tilt the camera slowly or tilt it fast -- every single time it took a photo when the horizon/treeline came into place.
And it does this on factory defaults with and without Magic Lantern. Lastly, I have a sneaking suspicion (but unconfirmed due to last of testing and opportunity) that using 1/4000 exposure increases the likelihood of this happening. In my daily photo-taking, I almost never have this problem. When I use 1/4000 in broad daylight, there seems to be a more likelihood that it will do this.
Today it was very annoying. I first noticed this problem a week after I bought my t3i body from Amazon (before going to Singapore) in February (received it on the 1st).
| 
